Benchmark Platinum-Edge: Operation-Service Manual
SECTION 5 – SAFETY DEVICE TESTING
OMM-0137_D • GF-211
•
7/16/2019
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5.2 LOW GAS PRESSURE TEST
Complete the instructions in Section 5.2.1 for BMK 750 – 2500 units, or in Section 5.2.2 for BMK
3000 – 6000 units, which have different Low and High Gas Pressure switches.
5.2.1 LOW GAS PRESSURE TEST: BMK 750 – 2500
To simulate a low gas pressure fault, refer to Figure
5-1a to 5-1c and perform the following
steps:
LOW Gas Pressure Test Instructions: BMK 750 – 2500
1. Remove the front panel from the boiler to access the gas train components.
2. Close the leak detection ball valve located at the Low Gas Pressure switch.
3. Remove the 1/4" NPT plug from the ball valve at the Low Gas Pressure switch.
4. Install a
0 - 16” W.C. (0 – 4.0 kPa)
manometer or gauge where the 1/4" plug was removed.
5. Slowly open the 1/4" ball valve near the Low Gas Pressure switch.
6. On the Controller, go to
Main Menu
Diagnostics
Manual
Run.
7. Enable the
Manual
Mode
parameter. The
Comm
LED will go off and the
MANUAL
LED
will light.
8. Adjust the Air/Fuel Valve position
between 25% and 30%
using the
+
(Plus) and
–
(Minus)
controls.
9. While the unit is firing, slowly close the external manual gas shut-off valve upstream of the
unit (not shown).
10. The unit should shut down and display a
Fault Lockout -
Gas Pressure
Fault
message at
approximately the pressure shown in Table 5-1 (the pressure setting of the Low Gas
Pressure switch):
TABLE 5-1: LOW Gas Pressure, ± 0.2” W.C. (± 50 Pa)
Benchmark Model
Natural Gas
Propane
BMK 750/1000 FM & DBB Single-Fuel
2.6” W.C. (648 Pa)
7.5” W.C. (1,868 Pa)
BMK 1500/2000 FM & DBB Single-Fuel
3.6” W.C. (897 Pa)
–
BMK 1500/2000 Dual-Fuel
4.4” W.C. (1,096 Pa)
2.6” W.C. (648 Pa)
BMK 1500/2000 DBB Dual-Fuel
2.6” W.C. (648 Pa)
2.6” W.C. (648 Pa)
BMK 2500 FM & DBB Single-Fuel
3.6” W.C. (897 Pa)
–
BMK 2500 Dual-Fuel
7.5” W.C. (1,868 Pa)
3.6” W.C. (897 Pa)
BMK 2500 DBB Dual-Fuel
7.5” W.C. (1,868 Pa)
3.6” W.C. (897 Pa)
11. Close the ball valve near the Low Gas Pressure switch (opened in Step 5).
12. Fully open the external manual gas shut-off valve (not shown) and press the Controller’s
CLEAR
button.
13. The fault message should clear, the
FAULT
indicator should go off, and the unit should
restart.
14. Upon test completion, close the ball valve, remove the manometer and replace the 1/4"
NPT plug removed in step 3.
